Synergists to aerosol insecticides



Patented Apr. 4, 1944 SYNERGISTS TO AEROSOL INSECTICIDES William N.Sullivan, Washington, D. 0., and Lyle D. Goodhue, Berwyn, Md., assignorsto the United States of America as represented by Claude R. Wickard,Secretary of Agriculture, and his successors in office No Drawing.Original application September 30, 1941, Serial No. 412,960. Divided andthis application January 7, 1944, Serial No. 517,362

(Granted under the act of March 3, 1883, as

3 Claims.

This application is made under the act of March 3, 1883, as amended bythe act of April 30, 1928, and the invention herein described andclaimed, if patented, may be manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment to us of any royalty thereon.

This is a division of our copending application for patent, Serial No.412,960, filed September 30, 1941.

and the added material a synergist. Therefore,

in these terms, the general object of our invention is the provision ofmaterials suitable as synergists for aerosol insecticides.

Another object of our invention is the provision of agents which willnot only increase the insecticidal action of materials known to possessOur invention relates materials which will some toxicity, but,.whichwill also impart insecticidal properties to materials which are known tobe non-toxic or to have a very low toxicity.

A further object of our invention is the provision of such agents actingas synergistawhich can be applied by dispersion simultaneously with andby the same methods used for the preparation of aerosol insecticides.

We have found that materials suitable for the purposes of this inventionbelong most frequently to the class of chemical compounds which aresurface active in non-aqueous solvents or which act as detergents innon-aqueous solvents. These compounds, in general, contain polargroupings such as the hydroxyl, the carboxyl, the amine, the ammonium,or the sulfonic acid, alone, in multiple, or in combination, which isattached to some long chain aliphatic radical, or, in some cases, anaromatic radical.

Substances acting as detergents or surface active agents in non-aqueousmedia can be easily applied by the usual methods of aerosol produc-'tion, but this invention is not limited to these substances becausedifferent methods of aerosol production can be usedwith different typesof amended April 30, 1928; 370 G. 757) synergists. In this class ofchemical compounds we have found the fatty'acids, the mono esters offatty acids and ethylene or propylene glycol, of glycerine or sorbitol,to be especially suitable as well as fatty acids in combination withamines such as methanolamine, sulfonated aryl and alkyl radicals aloneor combined with an amine.

There are many processe which can be used to apply these materials'inthe form of aerosols,

such as spraying into the atmosphere, vaporization, by chemicalreaction, by spraying on a heated surface, and so forth. Although thisinvention is not limited to any particular method of application, ourpreferred method of application comprises dissolving the synergist inthe insecticide, if the insecticide is a liquid, or dissolving it insome solvent common to both if a solid, and spraying the solution on aheated surface, whereby an aerosol is formed composed of both thesynergist and the insecticide.

A synergist to an insecticide in aerosol form is not necessarily also asynergist to an insecticide in spray form, even of the same compound.Ac-

tual tests have disclosed that an agent which possesses little or noeffect as a synergist to an insecticidal spray may be extremelyeffective as a synergist to an insecticidal aerosol. The reason for thisis not apparent, but it would seem that the mere wetting of the insectcannot explain the action.

The following results were obtained using synergists in accordance withthis invention. These results were obtained on the basis of preliminarytests first carried out in a small chamber of '7 cu. ft. and then on alarger scale in a 216 cu. ft. chamber. In each test from 500 to 600flies were used. Six-tenths of a pound of o-dichlorobenzene per 1000 cu.ft. gave only a 2% kill. However, when mixed with 0.16 lb. of oleic acidas a synergist, a kill was obtained. This same quantity of oleic acid,when used alone under the same conditions gave only a 1% kill. Lauricacid when used alone in the same amount, namely, 0.16 lb. per 1000 cu.it, gave only a 1% kill, but when used as a synergist with 0.6 lb. ofo-dichlorobenzene per 1000 cu. ft. a kill was obtained.

7 The same synergists were tested at other concentrations and it wasfound that little is gained by adding more than 10%.

The following is a list or substances which were tested as synergists ata concentration 01 0.06 lb. in 0.6 lb. of o-dichlorobenzene per1000 cu.it. against the houseflm the percentage, of kill in each case beingindicated in the right hand column:

Per cent kill Spermaceti V Diglycol laur 48 Sulionated naphthalene 60Salicylic 'acid I 91 Propylene glycol oleate 28 Myristic cid .49Propylene glycol laurate '14 Sorbitol laur V '59 Monoglycol laurate -r.56 Triethanolamine oleate.. 56 Lauryl sulfate 70 other insecticideswereused against the "American and German cockroach tration of 1.5 lbs. per1000 cu. ft. One-tenth of the insecticide was replaced by a synergist.A. mortality of 100% was obtained with the following:methylchloroacetate plus lauric acid, epichlorohydrin plus lauric acid,epichloroh'ydrin plus oleic acid, ethyl dichloroacetate plus lauricacid, ethyl dichloroacetate plus oleic acid, betachloroethylchlorocarbonate plus lauric acid,

chloroethane plus lauric acid, and o-dichlorobenzene plus lauric acid.In all cases where oleic acid was effective, lauric acid was-also foundto be efiective and vice versa. The kill without a synergist was alwaysless than 100% and usually less than 50%.

at a concen- Cit In a 1100- cu. ft. room, cockroaches, more than 5000were killed in 18 hours and none were found living, using 1 lbs. ofo-dichlorobenzene with 3% lauric acid and 2% oleic acid. Excellentresults were also obtained in a 3200 cu. ft. room.

' beta-chloroethylacetate plus lauric acid, tetra- Tests were alsoconducted against the carpet beetle larva, the confused flour beetlesand crickets. The halogenated esters in combination with any one ofthe'synergists mentioned above are extremely toxic to the confused flourbeetle and produce a high mortality to the carpet beetle larva.

Among 80 compounds tested against the housefly in the form of aerosols,in combination with synergists of the type mentioned above, are

3-chloroacenaphthene, 2-chlorofluorene, 3-chlorodibenzofuran,chlorinateddiphenyls, halogenated naphthalenes, halogenated esters,halogenated ketones, carbazole, thiocresol and halogenated phenols. Thesynergist was shown to be responsible in each case for an increase intoxicity.

Having thus described claim: I

1. An insecticide in aerosol form comprising ortho-dichlorobenzen-e andsalicylic acid.

2; An insecticide in aerosol'form comprising 3-chloroacenaphthene andsalicylic acid.

3. An insecticide in aerosol form comprising our invention, we

2-chlorofluorene and salicylic, acid.

WILLIAM N. SULLIVAN. LYLE D. GOODHUE.

naturally infested with

